1. Field of the Invention
The present invention relates to a crane with double wire guide and anchoring bracket arranged in the nacelle of a wind turbine, for hoisting-up and -down heavy parts of the wind turbine arranged in the nacelle, said crane comprises a yaw and an external winch with wire, located near the base of the wind turbine tower, said winch being connected via the wire guide to a pulley block comprising a crane hook at the end of the crane outrigger arm.
2. Description of Related Art
When servicing in particular larger wind turbines, mobile cranes located on the ground are often used. Said mobile cranes includes a high tower, which typically consists of sections defined lattice structure which is assembled before the crane is used. This results in a significant time consumption for the erection of the crane, which every time its position need to be amended, requires that the tower be dismantled. This results in high costs, which is undesirable.
Often wind turbines installed in wind farms where the turbines are serviced by a particular schedule, and for this purpose we have developed a crane system of the kind where a small crane davit-type first established in the turbine nacelle, where it is anchored to a stable structural parts then this crane is used to hoist parts for the aforementioned crane, whose games are arranged on the ground at the mill stand. The parts for the aforementioned crane typically consists of an anchoring bracket which is anchored to stable structural components in the nacelle, after which the actual crane in which the cable guide is included, placed and anchored on the anchoring console, then heavier parts of the wind turbine placed inside and outside the nacelle can be handled by crane, the remote control of the game.
Often wind turbines installed in wind farms where the turbines are serviced according to a specific schedule, and for this purpose has been developed a crane system of the kind stated in the preamble, where a small crane of the davit-type is first established in the turbine nacelle, where it is anchored to a stable structural parts, then this crane is used to hoist parts for the aforementioned crane, whose winces are arranged on the ground near the base of the wind turbine tower. The parts for the aforementioned crane typically consists of an anchoring console which is anchored to stable structural components in the nacelle, after which the actual crane in which the wire guide is included, placed and anchored on the anchoring console, then heavier parts of the wind turbine placed inside and outside the nacelle can be handled by crane, by remote control of the winch.
The problem with the use of this type of crane is however to prevent the wires to come into contact with each other when performing yawing with the crane, as this can cause them to become damaged, and even worse, torn apart, and consequently loss of load in the crane hook, with subsequent danger to personnel working within the crane's operating radius.
Wires are introduced from known positions and passed through a yaw which comprises a fixed outer drum, and a therein rotatable mounted inner drum to which the crane outrigger arm is attached, and where the rotation of the crane is performed by means of a yaw mechanism. The wires are further guided out of the inner drum to the crane outrigger arm from known positions to the crane arm and hoist block hanging on this, and it is recognized that a rotation/yawing at 360 degrees will not be possible to perform with cranes of this type, without the wires in contact with each other.